Based on the proposed capacity model of OAM-SM millimeter wave communication systems, the performance of capacity is simulated. Moreover, a conventional MIMO communication system [1]} are simulated and compared with the proposed OAM-SM millimeter wave communication systems in the following performance analysis.
The default simulation parameters are configured as follows: the carrier frequency is 60 GHz, the bandwidth is 20 MHz, the OAM state is 8, the transmission distance between the transmitter and receiver is \(d = 50\)  meters, the noise power spectral density is -174 dBm/Hz [2]}, [3]}, and the distance between transmission (receive) antenna elements is \(\xi = 20\lambda \)  [4]}, [5]}, [6]}. The OAM-SM communication systems are configured with 4 transmission antennas and 4 receive antenna pairs. The MIMO communication systems are configured with 4 transmission antennas and 4 receive antennas. The 4PSK modulation is adopted for OAM-SM and MIMO communication systems. The total transmit power of the MIMO communication system is configured to be equal to the transmit power of OAM-SM communication systems.
